When setting up a Reactor-Ready system, you insert the overhead stirrer motor’s support rod into the hole in the I-beam (also called the stirrer support I-brace).
If you cannot fit your overhead stirrer rod into the hole, you should remove the black plastic parts that are supplied inserted in the hole (one half on each side – gently prise out using a suitable implement), to increase the hole diameter. With the black pieces in place, stirrer rods of up to 13.5 mm diameter can be accommodated; removal allows stirrer rods of up to 16.5 mm to be inserted.
You can then use the knob on the I-beam above the hole to tighten the screw and secure the overhead stirrer’s support rod in place.
The procedure is the same for Reactor-Ready Duo.